1. Field of the Invention
The invention relates to a device for actuating locks on hatches or doors of vehicles, comprising a rotary latch in the lock that is spring-loaded into its open position, wherein the rotary latch, when the hatch or the door is closed, receives a lock member provided stationarily on the vehicle and is rotated into at least one defined position (locked position). The device further comprises a detent on the rotary latch into which, upon rotation of the rotary latch, a catch, pivotably and stationarily supported in the lock, drops so as to define a blocking position of the catch and to secure the locked position of the rotary latch. The device further comprises a catch spring that forces the catch into the blocking position. An actuation that is operated manually or by means of a motor is provided for lifting the catch from its blocking position into a release position in which the rotary latch is released. A snow load device is provided in the lock which, when actuated, holds the catch in the release position until the rotary latch has reached its open position.
2. Description of the Related Art
The classical components of a lock include a spring-loaded rotary latch which upon closing of the door cooperates with a stationary lock member and a spring-loaded, pivotably supported catch that, when closing the door, drops into at least one detent of the rotary latch. The described device also includes a so-called snow load device. The snow load device is needed when upon electric and/or manual actuation of the catch the rotary latch remains in its locked position and does not release the lock member. Despite actuation, the door cannot be opened in this situation.
This “snow load situation” occurs for a lock arranged on the rear hatch of a vehicle when a snow load is present on the closed rear hatch. The weight of the snow presses the rear hatch so tightly into the lock member that the return force of the seal and/or the spring load is not sufficient for transferring the rotary latch into the open position. The term “snow load situation” has been derived from this situation. Without a snow load device, the catch would be returned by the catch spring into the blocking position so that it drops into a detent of the rotary latch and therefore secures the rotary latch again in the locked position.
The snow load device has the task of securing the catch in the release position caused by its actuation until the rotary latch has actually reached its open position. The result is that after removal of the snow load from the rear hatch the already released rotary latch is returned by its spring load into the open position without this requiring renewed actuation.
Aside from such a snow load situation there are also other disturbance situations in these devices where the use of such snow load devices is very desirable. In the case of rotary latches that have in addition to the so-called main detent also a pre-detent, it can occur that a rotary latch that is secured by the catch in its main detent will not return quickly enough upon actuation of the catch into its open position but instead its pre-detent is engaged by the catch. It is then necessary to actuate the catch again; this is perceived as cumbersome. In this situation, such a snow load device is also helpful.
Locking devices with snow load devices of this kind are known in various embodiments. The device according to German patent 38 01 158 C1 requires several parts for securing the catch in its release position, e.g. a blocking lever with a stop arm, a driver pin on the rotary latch, and an auxiliary lever. The known snow load devices are expensive and require a large space.
U.S. Pat. No. 6,109,671 discloses a lock in which the force of the catch spring acts always in the same direction on the catch; however, this force can be made inactive by providing additional safety means. These safety means are comprised of a U-shaped hook bracket on a driver that is connected fixedly to the catch and of control surfaces as well as a projection on the rotary latch. In the snow load situation, the hook bracket engages from behind the projection so that the driver is supported on the rotary latch and generates a spacing between the rotary latch and the catch. The force of the catch spring that is still active in the snow load situation is transmitted by the driver onto the rotary latch. These securing means take up a large space within the lock.